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已有 1138 次阅读 2021-9-26 15:28 |个人分类:发表作品|系统分类:论文交流

发表期刊:ACS ES&T Engineering

论文题目:Energy Consumption of Brackish Water Desalination: Identifying the Sweet Spots for Electrodialysis and Reverse Osmosis

论文作者:Sohum K. Patel, P. Maarten Biesheuvel, and Menachem Elimelech

发表日期:May 14, 2021

论文摘要:Though electrodialysis (ED) and reverse osmosis (RO) are both mature, proven technologies for brackish water desalination, RO is currently utilized to desalinate over an order of magnitude more brackish water than ED. This large discrepancy in the adoption of each technology has yet to be thoroughly justified in the literature, particularly from the perspective of energy consumption. Hence, in this study, we performed a direct and systematic comparison of the energy consumption of RO and ED for brackish water desalination, precisely mapping out the ideal operational space of each technology for the first time. Using rigorous system-scale models for RO and ED, we determine the specific energy consumption and energy efficiency of each process over a wide range of brackish water conditions. Specifically, we investigate the effects of varying feed salinity, extent of salt removal, water recovery, and productivity to ultimately identify the operational sweet spots of each technology. By maintaining the same separation parameters (i.e., feed salinity, salt removal, water recovery) and productivity between RO and ED throughout the study, we ensure that our comparison of the technologies is valid and fair. Our results indicate that both RO and ED are capable of operating with high energy efficiency (>30%) for brackish water desalination, though for differing conditions. Particularly, we show that whereas ED excels for low feed salinities (<3 g L–1) and extents of salt removal, RO operates optimally for high salinity feeds (>5 g L–1), which require more extensive desalination. Through our in-depth energetic analysis, we provide guidance for future applications of RO and ED, emphasizing that increased implementation of ED will require significant reduction in the cost of ion-exchange membranes.


发表期刊:Accounts of chemical research

论文题目:Radical Carboxylative Cyclizations and Carboxylations with CO2

论文作者:Jian-Heng Ye, Tao Ju, He Huang, Li-Li Liao, Da-Gang Yu

发表日期:May 18, 2021

论文摘要:Carbon dioxide (CO2) is not only a greenhouse gas and a common waste product but also an inexpensive, readily available, and renewable carbon resource. It is an important one-carbon (C1) building block in organic synthesis for the construction of valuable compounds. However, its utilization is challenging owing to its thermodynamic stability and kinetic inertness. Although significant progress has been achieved, many limitations remain in this field with regard to the substrate scope, reaction system, and activation strategies.

Since 2015, our group has focused on CO2 utilization in organic synthesis. We are also interested in the vast possibilities of radical chemistry, although the high reactivity of radicals presents challenges in controlling selectivity. We hope to develop highly useful CO2 transformations involving radicals by achieving a balance of reactivity and selectivity under mild reaction conditions. Over the past 6 years, we along with other experts have disclosed radical-type carboxylative cyclizations and carboxylations using CO2.

We initiated our research by realizing the Cu-catalyzed radical-type oxytrifluoromethylation of allylamines and heteroaryl methylamines to generate valuable 2-oxazolidones with various radical precursors. Apart from Cu catalysis, visible-light photoredox catalysis is also a powerful method to achieve efficient carboxylative cyclization. In these cases, single-electron-oxidation-promoted C–O bond formation between benzylic radicals and carbamates is the key step.

Since carboxylic acids exist widely in natural products and bioactive drugs and serve as important bulk chemicals in industry, we realized further visible-light-promoted carboxylations with CO2 to construct such chemicals. We have achieved the selective umpolung carboxylations of imines, enamides, tetraalkylammonium salts, and oxime esters by successive single-electron-transfer (SSET) reduction. Using this strategy, we have also realized the dearomative arylcarboxylation of indoles with CO2. In addition to the incorporation of 1 equiv of CO2 per substrate, we have recently developed a visible-light photoredox-catalyzed dicarboxylation of alkenes, allenes, and (hetero)arenes via SSET reduction, which allows the incorporation of two CO2 molecules into organic compounds to generate valuable diacids as polymer precursors.

In addition to the two-electron activation of CO2, we sought to develop new strategies to realize efficient and selective transformations via single-electron activation of CO2. Inspired by the hypothetical electron-transfer mechanism of iron–sulfur proteins, we have realized the visible-light-driven thiocarboxylation of alkenes with CO2 using catalytic iron salts as promoters. The in-situ-generated Fe/S complexes are likely able to reduce CO2 to its radical anion, which could react with alkenes to give a stabilized carbon radical. Moreover, we have also disclosed charge-transfer complex (CTC) formation between thiolate and acrylate/styrene to realize the visible-light-driven hydrocarboxylation of alkenes with CO2 via generation of a CO2 or alkene radical anion. On the basis of this novel CTC, the visible-light-driven organocatalytic hydrocarboxylation of alkenes with CO2 has also been realized using a Hantzsch ester as an effective reductant.


发表期刊:ACS ES&T Water

论文题目:Temporal Trends of Short- and Medium-Chain Chlorinated Paraffins in Mollusks from the Chinese Bohai Sea during 2011–2018

论文作者:Yingjun Wang, Xindong Ma, Wei Gao, Chang Li, Lingyi Meng, Huifang Zhong, Yawei Wang, and Guibin Jiang

发表日期:April 9, 2021

论文摘要:Short-chain chlorinated paraffins (SCCPs) and medium-chain chlorinated paraffins (MCCPs) are among the most complex and commonly used chlorinated pollutants in the environment. Their temporal and spatial trends can be used to evaluate the effectiveness of regulations on their production and usage. In this study, mollusks (n = 308) were collected to study their temporal and spatial trends (as well as congener patterns) in different species collected from the Chinese Bohai Sea during 2011–2018. The total concentrations of SCCPs and MCCPs were 28.2–6026 ng/g of dry weight (dw) (mean of 578 ng/g of dw) and nd–4342 ng/g of dw (mean of 356 ng/g of dw), respectively. No obvious temporal or spatial trends of CPs in mollusks were found. However, the homologue profile variance and temporal trends of SCCPs and MCCPs across sampling years suggested changes in the composition of CP industrial products. Compared to the other species, oysters had the highest concentrations of CPs, implying that their bioaccumulation activity might be higher than those of other species. Upon combination of results of biological accumulative capacity and the correlation of CP concentrations among the different species, Neverita didyma, Meretrix meretrix, and Crassostrea talienwhanensis are more appropriate than other species for indicating the pollution of CPs in the Chinese Bohai Sea.


发表期刊:ACS ES&T Water

论文题目:Facilitated Activation of Peroxymonosulfate by Loading ZIF-8 on Fe3O4-MnO2 for Deep Mineralization of Bisphenol A

论文作者:Limei Dong, Yiming Li, Dafan Chen, Xiuping Chen, and Dan Zhang

发表日期:February 12, 2021

论文摘要:The hierarchically structured Fe3O4-MnO2-ZIF-8 composite was successfully synthesized and applied to activate peroxymonosulfate (PMS) for the degradation of bisphenol A (BPA) and other organic pollutants for the first time. Catalytic experiments revealed that the as-prepared Fe3O4-MnO2-ZIF-8 showed highly efficient catalytic activity and deep mineralization for BPA because of the loading of ZIF-8. When 60 mg/L BPA was degraded by the Fe3O4-MnO2-ZIF-8/PMS system, the removal efficiency of BPA reached 100% within 15 min and the TOC removal efficiency reached 80% within 9 min, values that were much higher than those of the catalysts reported recently. Fe3O4-MnO2-ZIF-8 can be separated conveniently from the aqueous phase under magnetic field control and shows better recyclability. Simultaneously, the Fe3O4-MnO2-ZIF-8/PMS system shows an excellent removal capability for other organic pollutants, such as phenol, tetracycline, p-hydroxybenzoic acid, and rhodamine B. Through radical quenching experiments and electron paramagnetic resonance tests, the mechanism of activation of PMS by Fe3O4-MnO2-ZIF-8 was investigated. ZIF-8 loaded on the surface of the Fe3O4-MnO2 composite can accept electrons generated from the Mn(II)/Mn(III)/Mn(IV) redox conjugate triplet and react with PMS to generate more •OH and SO4•–, thus significantly enhancing the catalytic performance. Additionally, on the basis of GC-MS analysis, the intermediates in the process of BPA degradation were tested and the possible degradation pathway was determined. This study indicates that Fe3O4-MnO2-ZIF-8 is a highly efficient catalytic material for PMS-based AOPs for the removal of various pollutants from water.



论文题目:Design of an AIE-Active Flexible Self-Assembled Monolayer Probe for Trace Nitroaromatic Compound Explosive Detection

论文作者:Guozhi Wang, Mingliang Li, Qianhui Wei, Yuhua Xiong, Jie Li, Ziwei Li, Jinyao Tang, Feng Wei, and Hailing Tu

发表日期:May 28, 2021

论文摘要:In this work, a series of molecules TPE-PA-n (n = 3–11) were designed with classic aggregation-induced emission (AIE) 1,1,2,2-tetraphenylethene (TPE) for self-assembled monolayers (SAMs), which are applied for the detection of trace nitroaromatic compound (NAC) explosives. Phosphoric acid that acts as an anchor is used to connect with TPE through alkyl chains of various lengths. It is found that the alkyl chains play a role in pulling TPE luminogens to aggregate for light emission, which can affect the fluorescence and sensing performance of the SAMs. Ulteriorly, a model is built to explore the influence of the alkyl chain length on the device performance, which is determined by the three effects of the alkyl chain: flexibility, the coupling effect, and the odd–even effect. By comparison, the functional molecules with the chain length of 8 were finally selected and further applied for NAC sensors. By means of fluorescence spectra, the SAM sensor was proved to have good stability, reversibility, selectivity, and sensitivity, and its detection limits for trinitrotoluene, dinitrotoluene, and nitrobenzene were 1.2, 6.0, and 35.7 ppm, respectively. This work provides new ideas for the design and preparation of flexible sensors for trace NAC detection with high performance, low cost, and easy operation.



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